1. Field of the Invention
This invention relates generally to a "hybrid" exposure control system for a photographic camera apparatus and, more particularly, to a "hybrid" exposure control system for a photographic camera apparatus utilizing a quench strobe.
2. Description of the Prior Art
So-called "hybrid" exposure control systems are well known in the art and generally operate to control exposure in response to both firing a flash lamp at an appropriate aperture size calculated to generally correspond to the determined camera-to-subject distance in accordance with the inverse square law of light and the subsequent detection and integration of reflected artificial illumination from the scene to provide a shutter blade closing command signal. This makes possible an increased degree of exposure correction since a slight error in the determination of camera-to-subject range resulting in a corresponding error in the aperture size at which the flash lamp is fired can be easily compensated by the detection and integration of the reflected artificial illumination to provide the shutter blade closing command signal. Such "hybrid" exposure control systems are disclosed in U.S. Pat. No. 3,464,332, entitled "Automatic Exposure Control System", by R. H. Davison et al., issued Sept. 2, 1979 in common assignment herewith, U.S. Pat. No. 3,975,744, entitled "Automatic Exposure Control System", by B. K. Johnson et al., issued Aug. 17, 1976, and U.S. Pat. No. 4,047,190, entitled "Hybrid Exposure Control System Employing Dual Maximum Blade Displacement", by B. K. Johnson et al., issued Sept. 6, 1977. Such "hybrid" exposure control systems as those disclosed above contemplate only the use of an ordinary flash lamp as the source of artificial illumination since the burn time of an ordinary flash lamp is sufficiently long as to allow the exposure to be terminated by the closing shutter blades. Thus such systems have not heretofore been adapted for use with electronic flash.
Therefore, it is a primary object of this invention to provide a "hybrid" exposure control system for a photographic camera apparatus utilizing an electronic flash or strobe of the quench type for its source of artificial illumination.
It is a further object of this invention to provide a "hybrid exposure" control system in which a quench strobe is fired at an appropriate aperture size corresponding to the determined camera-to-subject distance and wherein the strobe is subsequently quenched as a function of reflected scene light detected in correspondence with the reflected scene light admitted to the film plane during the exposure interval.
Other objects of the invention will be in part obvious and will in part appear hereinafter. The invention accordingly comprises a mechanism and system possessing the construction, combination of elements and arrangement of parts which are exemplified in the following detailed disclosure.